Composite material spray forming device and method based on melt dispersion in-situ reaction

Abstract

The invention discloses a composite material spray forming device and method based on melt dispersion in-situ reaction, and the method comprises the following steps: starting a mechanical stirring-melt dispersion device in a composite reaction crucible containing a melt A to rotate, and then enabling a melt B in a crucible II to flow into a disperser through a discharge pipe II; dispersing the melt B into liquid drops through a disperser under rotation, dripping the liquid drops into the melt A, carrying out an in-situ reaction with the melt A under the synergistic effect of mechanical stirring to obtain a composite melt containing in-situ reinforced particles, after the in-situ reaction is completed, heating, continuously carrying out mechanical stirring to obtain a jet melt, and then enabling the jet melt to flow into a nozzle to obtain the in-situ reinforced particles. According to the preparation method, mechanical stirring (a three-dimensional flow field), melt dispersion, liquid phase in-situ reaction and a spray forming process are combined, and in-situ generation and uniform dispersion of a reinforced phase are achieved.

Description

Technical Field

[0001] The invention belongs to the technical field of metal matrix composite material preparation, and in particular relates to a composite material injection molding device and method based on melt dispersion in-situ reaction. Background Art

[0002] Metal matrix composites (MMCs) have become the core material for high-end equipment manufacturing due to their excellent strength, wear resistance and high temperature performance. At present, the main difficulties faced by metal matrix composites in the preparation process include: interface bonding problems, coarsening and agglomeration of reinforcement phases, and high costs. First, the interface bonding strength between the metal matrix and the reinforcement phase (such as ceramic particles, fibers, etc.) directly affects the performance of the material. If the bonding is poor, it will lead to stress concentration and interface debonding, reducing the mechanical properties of the material. Secondly, except for the powder metallurgy method with a lengthy process, other preparation methods of composite materials are difficult to get rid of the problems of coarsening and agglomeration of the reinforcement phase. Therefore, how to optimize the interface bonding, refine the reinforcement phase, improve the dispersion of the reinforcement phase, simplify the processing technology and reduce the cost are key issues that need to be solved in the field of metal matrix composite preparation.

[0003] As an important process for efficient forming of metal matrix composites (MMCs), spray forming technology can theoretically combine the advantages of rapid solidification and near-net-shape forming by atomizing the metal melt and directly depositing it into a near-net-shape blank. However, the existing technology has significant defects in the introduction of reinforcement phase, reaction control and process continuity, as shown below:

[0004] Traditional spray forming processes mostly use the method of introducing premixed reinforcements, that is, the reinforcements (such as SiC, TiB2, etc.) are directly added to the matrix melt during the smelting stage, and then atomized and deposited after stirring. This method has problems with interface contamination and weak bonding, particle segregation and agglomeration. Some improved spray forming technologies attempt to generate reinforcement phases through in-situ reactions in the melt, but are limited by problems such as incomplete reactions and phase coarsening. In addition, existing spray forming equipment generally adopts a split design, with smelting, reinforcement mixing, atomization and deposition as independent modules, resulting in process interruptions and inefficiency, and a surge in energy consumption and costs.

[0005] In order to solve the difficulties of existing composite material injection molding technology, the present invention uses an integrated design of dispersed injection-in-situ reaction-mechanical stirring-injection molding to specifically solve the above bottlenecks and promote the upgrading of MMCs injection molding technology towards high performance, high precision and low energy consumption. Summary of the invention

[0006] Aiming at the common problems in the prior art that the nano-reinforcing phase is prone to agglomeration in the mechanical mixing method and the reaction interface is limited in the in-situ synthesis method, resulting in the coarsening of the reinforcing phase (>500 nm), the first object of the present invention is to provide a composite material spray forming method based on melt dispersion in-situ reaction. The method provided by the present invention disperses the reaction alloy melt into millimeter-sized droplets through melt dispersion and mechanical stirring, combines a three-dimensional high-intensity turbulent flow field, increases the in-situ reaction interface area by several orders of magnitude, obtains a melt with ultra-fine reinforcement phase and distribution uniformity >95%, and then combines the ultra-high cooling rate of the atomization process to strengthen the solidification interface to capture the strengthening particles and inhibit the segregation of the reinforcement phase during solidification, ensuring the uniform distribution of nano-scale reinforcement phase inside the matrix.

[0007] The second object of the present invention is to provide a composite material spray forming device based on melt dispersion in-situ reaction.

[0008] In order to achieve the above object, the present invention adopts the following technical solutions:

[0009] The present invention provides a composite material spray forming method based on melt dispersion in-situ reaction. Start the mechanical stirring-melt dispersion device in the composite reaction crucible containing melt A to rotate, then flow melt B in the No. II crucible into the disperser through the No. 2 discharge pipe. The disperser disperses melt B into droplets under rotation and drops them into melt A. Under the synergistic action of mechanical stirring, an in-situ reaction occurs with melt A to obtain a composite melt containing in-situ strengthening particles. After the in-situ reaction is completed, the temperature is raised, and mechanical stirring continues to obtain a spray melt. Then the spray melt flows into the corresponding 3 nozzles through 3 lower liquid outlets arranged side by side at intervals at the bottom of the composite reaction crucible. The spray melt is atomized by an air atomization medium to form a jet and deposited on the tray to obtain the composite material;

[0010] The viscosity of melt A is higher than that of melt B;

[0011] The mechanical stirring-melt dispersion device includes a stirring rod, a stirring paddle fixed at the bottom of the stirring rod, and a disperser fixed on the stirring rod above the stirring paddle. The disperser is a porous structure;

[0012] The 3 nozzles are arranged at intervals along the radial direction of the tray; the one close to the central axis of the tray is the inner ring nozzle, the one far from the central axis of the tray is the outer ring nozzle, and the middle one is the central nozzle;

[0013] The superheat degree of the spray melt is 150~300 °C;

[0014] The flow rate of any one of the lower liquid outlets is 0.1~0.5 cm 3 / s;

[0015] The spraying angle of the outer ring nozzle is 30 - 50°, the spraying angle of the inner ring nozzle is 0 - 20°, and the spraying angle of the middle nozzle is 0 - 50°;

[0016] The temperature of the gas atomization medium is 20°C to 100°C, the pressure of the gas atomization medium is 0.5 - 1 MPa, and the flow rate of the gas atomization medium is 20 - 50 L / min;

[0017] The rotation speed of the tray is 30 - 60 rpm, the lifting speed is 0.5 - 7 mm / s, and the receiving distance is 100 - 900 mm.

[0018] In the present invention, a mechanical stirring - melt dispersion device is adopted. First, melt B is passed through a disperser, so that melt B, under the dynamic action of rotational centrifugal force, passes through the through - holes of the disperser in the form of high speed and high pressure. The melt is dispersed into fine droplets or streams, and the dispersed droplets are dropped into melt A. Under the synergistic action of mechanical stirring, an in - situ reaction occurs with melt A, greatly increasing the specific surface area of the reaction, effectively increasing the in - situ reaction interface, refining the in - situ strengthening phase particles. In addition, the combination of melt dispersion and the three - dimensional flow field formed by mechanical stirring enables the melt and the refined in - situ strengthening phase particles to be more evenly distributed in the entire inner region of the crucible. After the in - situ reaction is completed, mechanical stirring continues, further making the in - situ strengthening particles evenly dispersed in the matrix. At the same time, the temperature is raised to increase the superheat of the melt, and under the synergistic action of mechanical stirring, the apparent viscosity of the melt is reduced, obtaining a spraying melt with low apparent viscosity, high superheat, and excellent fluidity. Then, the spraying melt flows into the nozzle, and the spraying melt is atomized by the gas atomization medium to form a jet and deposited onto the tray to obtain the composite material.

[0019] In the present invention, it is necessary to control the passage of low - viscosity melt B through the disperser. If the placement order of melt B and melt A is reversed, it will lead to poor melt dispersion effect, unable to obtain the maximum in - situ reaction interface, and resulting in coarsening of the strengthening particles.

[0020] In the present invention, on the one hand, by controlling the superheat of the atomized melt (the temperature difference between the melt temperature and the liquidus) within the scope of the present invention and synergistically with mechanical stirring, a spraying melt with good fluidity is obtained. On the other hand, through the synergy of the superheat of the atomized melt and the temperature of the gas atomization medium, an ultra - high cooling rate is formed, strengthening the capture of the strengthening particles by the solidification interface, inhibiting the segregation of the reinforcing phase during solidification, ensuring the uniform distribution of the nano - scale reinforcing phase within the matrix. At the same time, controlling the temperature of the gas atomization medium within the scope of the present invention to avoid too low temperature of the gas atomization medium, thereby avoiding complete solidification of the particles during the spray deposition process and ensuring plastic - deformation bonding between the particles during deposition.

[0021] In addition, experiments have found that spray deposition requires relatively low atomization pressure and gas flow rate, so that the particle size during the spray deposition process is slightly larger (80 - 150 μm), avoiding complete solidification and ensuring plastic deformation bonding between particles during deposition. Too low atomization pressure and gas flow rate will lead to uneven particle distribution and form a sparse edge area; too high will cause the particle flight speed to be too fast, making it easy to rebound or break when hitting the substrate, reducing the deposition efficiency; too high will also accelerate particle cooling, making it difficult to achieve plastic deformation bonding between particles.

[0022] In addition, in the present invention, three "linearly arranged" lower liquid outlets are provided at the bottom of the composite reaction crucible. The flow rates of the three liquid outlets are the same, and the melt flow rate of the liquid outlet is 0.1 - 0.5 cm 3 / s, which can ensure the uniformity and tightness of deposition. If the flow rate is too low, the number of droplets will be insufficient, resulting in a loose deposition layer and a decline in mechanical properties; if the flow rate is too high, melt splashing and local accumulation will occur. At the same time, the setting of three nozzles provides a multi-source input of spray deposition powder, effectively improving the spray efficiency and the size of the deposited part; by adjusting the spray angles of the three nozzles and controlling the flow rate of the lower liquid outlet, matching the rotation speed and lifting speed of the tray, the circumferential uniformity of the deposited body and the interlayer consistency in the axial direction are respectively achieved. This coordination avoids "stripes" or "holes" and realizes dense and defect-free composite deposition.

[0023] However, the spray angles of the outer ring nozzles and the inner ring nozzles need to be effectively controlled. Among them, the outer ring nozzles need to adopt a larger spray angle to compensate for the influence of centrifugal force. By increasing the angle, the jet flow inclines towards the inner side of the tray, avoiding particles flying away from the tray due to centrifugal force, counteracting the centrifugal force, and ensuring that the jet flow can reach the preset outer ring position. The inner ring nozzles are preferably used with a smaller spray angle because the linear velocity in the central area of the tray is low, and the jet flow diffusion needs to be reduced to avoid excessive accumulation of particles under low centrifugal force. Vertical or small-angle spraying can focus the jet flow and improve the deposition density.

[0024] In the present invention, the receiving distance refers to the distance between the top of the tray and the nozzle.

[0025] In a preferred embodiment, the corresponding raw materials are selected according to the composition of alloy A. All the raw materials of alloy A are placed in crucible No. I and heated to obtain melt A, and then melt A is flowed into the preheated and heat-insulated composite reaction crucible through the No. 1 discharge pipe, or a part of the raw materials of alloy A is placed in crucible No. I and heated to obtain melt A1, and another part of the raw materials of alloy A is placed in the composite reaction crucible and heated to obtain melt A2. Then melt A1 is flowed into the composite reaction crucible through the No. 1 discharge pipe and mixed with melt A2 to form melt A. The corresponding raw materials are selected according to the composition of alloy B and placed in crucible No. II and heated to obtain melt B.

[0026] In the actual operation process, when there are powder raw materials in the raw materials of melt A that are extremely easy to float on the surface of the melt (such as Cu2O, graphite powder), this part of the powder raw materials needs to be placed in a composite reaction crucible to ensure that the in-situ reaction in the composite reaction crucible proceeds according to the designed ratio. If there are no powder raw materials that are easy to float, placing all of alloy A in crucible No. I and heating it to melt is conducive to the continuous production of materials.

[0027] In the present invention, alloy A and alloy B are systems that can form high-temperature stable second-phase strengthening particles through in-situ liquid-phase reactions. For example, the in-situ reaction system combinations of the said alloy A and alloy B are: Cu-Cu2O and Cu-Al (generating Al2O3 particles), Cu-Cu2O and Cu-Cr (generating Cr2O3 particles), Cu-Cu2O and Cu-Ti (generating TiO2 particles), Cu-Cu2O and Cu-Zr (generating ZrO2 particles), Cu-Hf and Cu-B (generating HfB2 particles), Cu-Zr and Cu-B (generating ZrB2 particles), Al-Ti and Al-B (generating TiB2 particles), Cu-Ti and Cu-B (generating TiB2 particles). In the actual operation process, according to the viscosity of the alloy melt, the one with higher viscosity is used as alloy A, and the one with lower viscosity is used as alloy B. The melt B formed after melting alloy B, through a disperser, such as Cu-Ti melt and Cu-B melt, and the viscosity of Cu-B melt is relatively lower. In order to obtain a better melt dispersion effect, the Cu-B melt is placed in crucible No. II.

[0028] In a preferred embodiment, the in-situ strengthening particles are selected from at least one of Al2O3, Cr2O3, TiO2, ZrO2, HfB2, ZrB2, and TiB2.

[0029] In a preferred embodiment, the flow rate of the melt B flowing into the disperser through the No. 2 discharge pipe is 5 - 15 cm 3 / s. By controlling the flow rate within this range, it can not only have a higher efficiency but also avoid the merging of melt droplets caused by too large a flow rate, thus resulting in a poor melt dispersion effect.

[0030] In a preferred embodiment, the distance between the No. 2 discharge pipe and the top of the disperser in the height direction is controlled within 10 - 20 mm. In the horizontal direction, the distance between the outlet end of the No. 2 discharge pipe and the center of the disperser is controlled within 15 - 25 mm. By controlling the distance between the No. 2 discharge pipe and the disperser within this range, the melt passes through the disperser at a position close to the center of the disperser, and the melt dispersion effect is optimal, and the refinement effect of the finally formed second-phase particles is the best. The center of the disperser refers to the vertical center line of the disperser.

[0031] In a preferred embodiment, during the in-situ reaction process, the temperature difference between the upper and lower layers of melt A and melt B is controlled ≤ 20°C.

[0032] In a preferred embodiment, during the in-situ reaction process, the temperature of melt B is the melting point of alloy B + 50 to 200 °C, and the superheat of the composite melt is 50 to 100 °C. In the present invention, during the in-situ reaction, the temperature of melt B is controlled to be 50 to 200 °C above the melting point of alloy B, and the superheat of the composite melt is precisely controlled to be 50 to 100 °C. Finally, the reinforcing phase formed by the in-situ reaction is the most refined.

[0033] In a preferred embodiment, in the mechanical stirring-melt dispersion device, the distance between the disperser and the stirring paddle is 40 - 60 mm; during the in-situ reaction process, by moving the mechanical stirring-melt dispersion device up and down, the depth of the stirring paddle extending into the melt is controlled to be 40 - 60% of the total depth of the melt, and the distance from the bottom end of the disperser to the liquid surface is controlled to be 25 - 50 mm. By controlling the distance between the disperser and the stirring paddle and the depth of the stirring paddle extending into the melt within the above ranges, the optimal stirring effect can be obtained, and the synergistic effect between the disperser and the stirring paddle is the best, and finally the performance of the composite material is the best.

[0034] In a preferred embodiment, the disperser is selected from a conical dispersing member or a circular dispersing member. The conical dispersing member includes a conical dispersing disk, and multiple rows of holes are arranged in a circumferential array on the conical dispersing disk. Each row includes multiple through holes spaced along the generatrix direction; the circular dispersing member includes a circular dispersing disk, and multiple rows of holes are arranged in a circumferential array on the circular dispersing disk. Each row includes multiple through holes spaced along the radial direction;

[0035] On the outer side wall of the conical dispersing disk, a chute is provided between any two rows of holes; or on the inner side wall of the conical dispersing disk, a rib is provided between any two rows of holes; on the upper surface of the circular dispersing disk, a rib is provided between two rows of holes;

[0036] In the conical dispersing disk or the circular dispersing disk, the aperture of any one through hole is 2 - 3 mm, and the distribution density of the through holes is 0.5 - 1.5 per cm 2 ;

[0037] The thickness of the conical dispersing disk or the circular dispersing disk is 2 - 9 mm.

[0038] The disperser provided by the present invention arranges a number of through holes in a periodic array in the dispersion plate, effectively ensuring the uniformity of the size of the melt-dispersed droplets. Controlling the aperture and distribution of the through holes within the scope of the present invention results in the optimal refinement effect. If the aperture is too large, it will cause droplet coarsening and insufficient reaction interface; if the aperture is too small, it will also affect the dispersion effect due to the increased melt flow resistance. At the same time, controlling the thickness of the dispersion plate within the scope of the present invention can ensure the continuous passage of the melt through the dispersion and outflow. If the plate body is too thick, it will affect the continuity of the melt dispersion. In addition, in the present invention, the chute or rib is arranged at intervals between two rows of holes. For the chute and rib, firstly, it can exert a stronger shearing force on the melt to disperse and fragment the melt and prevent droplet coalescence; secondly, it drives the melt to rotate, enabling the melt to obtain a stronger centrifugal effect and a greater centrifugal force. This enhanced centrifugal effect promotes the rapid dynamic equilibrium of the melt in the disperser, ensuring both the stable outflow of the melt through the round holes and the edge of the disperser and avoiding the retention and accumulation of the melt in the dispersion cavity, achieving an excellent continuous and stable melt uniform dispersion effect.

[0039] In a preferred embodiment, the conical dispersing member is selected from one of the No. 1 conical dispersing member, the No. 2 conical dispersing member, and the No. 3 conical dispersing member. The No. 1 conical dispersing member includes a No. 1 conical dispersion plate, and multiple rows of holes are arranged in a circumferential array on the No. 1 conical dispersion plate. Each row includes a plurality of through holes evenly spaced along the generatrix direction; the distance between adjacent through holes in each row is 3 - 6 mm. On its outer side wall, a chute is arranged between any two rows of holes; the depth of the chute is 3 - 5 mm, and the width is 2 - 8 mm. The angle between the generatrix of the No. 1 conical dispersion plate and the horizontal plane is 5 - 60°; preferably 15 - 45°.

[0040] The No. 2 conical dispersing member includes a No. 2 conical dispersion plate. The No. 2 conical dispersion plate is an inverted cone. Multiple rows of holes are arranged in a circumferential array on the No. 2 conical dispersion plate. Each row includes a plurality of through holes evenly spaced along the generatrix direction; the distance between adjacent through holes in each row is 8 - 15 mm. On its inner side wall, a rib is arranged between any two rows of holes; the height of the rib is 3 - 5 mm, and the width is 2 - 4 mm; the angle between the generatrix of the conical dispersion plate and the horizontal plane is 30 - 45°.

[0041] The No. 3 conical dispersing member includes a No. 3 conical dispersion plate. The No. 3 conical dispersion plate is an inverted cone. Multiple rows of holes are arranged in a circumferential array on the No. 3 conical dispersion plate. Each row includes a plurality of through holes evenly spaced along the generatrix direction. The distance between adjacent through holes in each row is 4 - 12 mm. On its inner side wall, a rib is arranged between any two rows of holes; the height of the rib is 1.5 - 2.5 mm, and the width is 3 - 6 mm; the angle between the generatrix of the conical dispersion plate and the horizontal plane is 10 - 30°.

[0042] In the present invention, the conical dispersion disks provided are all the lateral surfaces of frustum cones, i.e., frustums of a cone. Among them, the conical dispersion disk of the No. 1 conical dispersion member is the lateral surface of a frustum with a smaller upper base and a larger lower base, and the No. 2 and No. 3 conical dispersion members are inverted cones, and their conical dispersion disks are the lateral surfaces of frustums with a smaller lower base and a larger upper base.

[0043] In a preferred embodiment, multiple rows of holes are arranged in a circumferential array on the disk surface of the circular dispersion disk. Each row includes a plurality of through holes evenly spaced along the radial direction. The spacing between adjacent through holes in each row is 5 - 10 mm. And above the disk surface, a rib is provided between any two rows of holes. The height of the rib is 3 - 5 mm, and the width is 3 - 8 mm.

[0044] In the present invention, a No. 1 conical dispersion member, a No. 2 conical dispersion member, a No. 3 conical dispersion member, and a circular dispersion member are provided. All four dispersers are made of graphite to better match different melts and obtain a better refinement effect.

[0045] In a further preferred embodiment, the material of the disperser is graphite. When the melt viscosity of melt B < 10 mPa·s and the wetting angle between melt B and graphite < 120°, the disperser is selected from the No. 2 conical dispersion member. When the melt viscosity of melt B > 10 mPa·s and the wetting angle between melt B and graphite < 120°, the disperser is selected from the No. 1 conical dispersion member. When the melt viscosity of melt B < 10 mPa·s and the wetting angle between melt B and graphite > 120°, the disperser is selected from the No. 3 conical dispersion member. When the melt viscosity of melt B > 10 mPa·s and the wetting angle between melt B and graphite > 120°, the disperser is selected from the circular dispersion member.

[0046] In a preferred embodiment, the stirring paddle is selected from one of stirring paddle A, stirring paddle B, and stirring paddle C. Stirring paddle A is a straight - blade stirring paddle. Stirring paddle B is an inclined - blade stirring paddle, and its blade forms an angle of 30° with the horizontal plane. Stirring paddle C is an inclined - blade stirring paddle, and its blade forms an angle of - 30° with the horizontal plane.

[0047] In a further preferred embodiment, when the density difference between the composite melt and the in - situ reinforcing particles does not exceed 0.3 g / cm 3 , the stirring paddle is selected from stirring paddle A. When the density difference between the composite melt and the in - situ reinforcing particles exceeds 0.3 g / cm 3 , and the density of the composite melt is greater than the density of the in - situ reinforcing particles, the stirring paddle is selected from stirring paddle B. When the density difference between the composite melt and the in - situ reinforcing particles exceeds 0.3 g / cm 3 , and the density of the composite melt is less than the density of the in - situ reinforcing particles, the stirring paddle is selected from stirring paddle C.

[0048] In the present invention, a suitable disperser is selected to ensure a good dispersion effect of the alloy melt B, and a suitable stirring paddle is selected to ensure a good dispersion effect of the in-situ particles in the composite melt. Through the combination of the type of the disperser and the type of the stirring paddle, the in-situ strengthening particles are fully refined and evenly distributed.

[0049] In a preferred embodiment, during the in-situ reaction, the rotational speed of the mechanical stirring-melt dispersion device is 100-150 r / min. During the entire in-situ reaction process, the rotational speed of the mechanical stirring-melt dispersion device should be kept constant to ensure the continuity of the melt dispersion process. Too low a rotational speed at this stage will result in poor melt dispersion effect, and too high a rotational speed will cause the dispersed melt to splash onto the inner wall of the crucible, affecting the progress of the in-situ reaction.

[0050] In a preferred embodiment, after the in-situ reaction is completed, other alloy raw materials are continuously added to the composite melt. There are two main purposes: one is to introduce other alloying elements into the matrix to facilitate the introduction of other strengthening phases (such as precipitation strengthening) during the subsequent heat treatment of the material; the other is to improve the wettability between the composite melt and the in-situ strengthening particles and promote the dispersed distribution of the in-situ strengthening particles.

[0051] In a preferred embodiment, after the in-situ reaction is completed, the temperature is raised, and mechanical stirring is continued for 5-10 min to obtain a spray melt. Then, the spray melt flows into a nozzle, and the spray melt is atomized by an air atomization medium to form a jet and deposited onto a tray to obtain a composite material. During the process of continuously carrying out mechanical stirring to obtain the spray melt and during the deposition process, the rotational speed of the mechanical stirring-melt dispersion device is controlled to be 200-300 r / min, and at the same time, electromagnetic stirring is carried out, and the frequency of the electromagnetic stirring is controlled to be 60-90 Hz, and the magnetic field strength is 0.2-0.3 T.

[0052] In a further preferred embodiment, during the process of continuously carrying out mechanical stirring to obtain the spray melt and during the deposition process, the rotational speed of the mechanical stirring-melt dispersion device is cyclically fluctuated at 200-230 r / min, 230-270 r / min, and 270-300 r / min, and the fluctuation period is 5-8 s. For example, 200 r / min → 250 r / min → 300 r / min → 200 r / min → 250 r / min → 300 r / min, such periodic fluctuations, and each rotational speed is maintained for 5-8 s. During the atomization process, the melt flows at a high speed, and the strengthening particles are prone to agglomeration due to density difference or shear force. Therefore, higher particle dispersion is required. Therefore, by adopting cyclic stirring at a fluctuating high rotational speed, stronger turbulence can be obtained in the melt, so that the strengthening particles can achieve a better dispersion effect, and at the same time, in cooperation with electromagnetic stirring, the apparent viscosity of the melt is reduced, and the atomization effect is improved.

[0053] The present invention also provides a composite material spray forming device based on in-situ reaction of melt dispersion, including: crucible No. I, crucible No. II, composite reaction crucible, mechanical stirring-melt dispersion device, and spraying device;

[0054] The crucible No. I is communicated with the composite reaction crucible through a No. 1 discharge pipe, and the crucible No. II is communicated with the composite reaction crucible through a No. 2 discharge pipe;

[0055] The composite reaction crucible is provided with 3 groups of liquid outlets arranged side by side at intervals. Any group of liquid outlets consists of an upper liquid outlet and a lower liquid outlet. Any group of liquid outlets is provided with a No. 3 stopper rod perpendicular thereto, and the No. 3 stopper rod is connected to a horizontal transmission device through a bolt;

[0056] The mechanical stirring-melt dispersion device penetrates through the top center of the composite reaction crucible and extends into the interior of the composite reaction crucible; the mechanical stirring-melt dispersion device includes a stirring rod, a stirring paddle fixed at the bottom of the stirring rod, and a disperser fixed on the stirring rod above the stirring paddle; the disperser is of a porous structure and is used for dispersing the melted melt in the crucible No. II into liquid droplets;

[0057] The spraying device includes a spraying chamber, 3 nozzles, a lifting and rotating device, and a tray; the top end of the spraying chamber is connected to the composite reaction crucible. The 3 nozzles, the lifting and rotating device, and the tray are all arranged in the spraying chamber. The 3 nozzles are arranged at intervals along the radial direction of the tray, and the 3 nozzles are correspondingly connected to the 3 groups of liquid outlets in the composite reaction crucible; among them, the nozzle close to the central axis of the tray is the inner ring nozzle, the nozzle far from the central axis of the tray is the outer ring nozzle, and the middle one is the central nozzle; the 3 nozzles are used for atomizing the spraying melt flowing out of the liquid outlet of the composite reaction crucible to form a jet and depositing it on the top surface of the tray. The lifting and rotating device and the tray have the same vertical central axis, and the lifting and rotating device drives the tray to rotate around the central axis and move up and down along the central axis.

[0058] In a preferred solution, the crucible No. I is provided with a No. 1 stopper rod, and the crucible No. II is provided with a No. 2 stopper rod. The No. 1 stopper rod and the No. 2 stopper rod are respectively connected to a vertical transmission device. Through the vertical transmission device, the vertical movement of the No. 1 stopper rod and the No. 2 stopper rod is controlled, so as to control the opening and closing of the liquid outlets of the crucible No. I and the crucible No. II and the melt flow rate of the liquid outlets.

[0059] In a preferred solution, the mechanical stirring-melt dispersion device further includes a servo motor and a planetary gear reducer. The servo motor is located outside the composite reaction crucible and is used to drive the stirring paddle and the disperser to rotate, and the rotation speed range is 0-1000 r / min. By using a high-precision servo motor as the driving source and equipped with a planetary gear reducer, the drive shaft, stirring paddle blades and other components are driven to rotate, so as to realize the stepless speed change of the stirring paddle within the range of 0-1000 r / min.

[0060] Preferably, the stirring rod in the mechanical stirring-melt dispersion device is composed of a long rod and a short rod connected by threads from top to bottom.

[0061] Preferably, in the mechanical stirring-melt dispersion device, the distance between the disperser and the stirring paddle is 40-60 mm.

[0062] Preferably, the disperser is selected from a conical dispersing member or a circular dispersing member. The conical dispersing member includes a conical dispersing disk, and multiple rows of holes are arranged in a circumferential array on the conical dispersing disk. Each row includes multiple through holes spaced along the generatrix direction; the circular dispersing member includes a circular dispersing disk, and multiple rows of holes are arranged in a circumferential array on the circular dispersing disk. Each row includes multiple through holes spaced along the radial direction;

[0063] On the outer side wall of the conical dispersing disk, a chute is provided between any two rows of holes; or on the inner side wall of the conical dispersing disk, a rib is provided between any two rows of holes; on the upper surface of the circular dispersing disk, a rib is provided between two rows of holes;

[0064] In the conical dispersing disk or the circular dispersing disk, the aperture of any one through hole is 2-3 mm, and the distribution density of the through holes is 0.5-1.5 per cm 2 ;

[0065] The thickness of the conical dispersing disk or the circular dispersing disk is 2-9 mm.

[0066] Further preferably, the conical dispersing member further includes a fixing ring A fixed above the conical dispersing disk and coaxial with the conical dispersing disk, and the circular dispersing member further includes a fixing ring B fixed above the circular dispersing disk and coaxial with the circular dispersing disk. The outer diameters of the fixing ring A and the fixing ring B are both 15-20 mm, and the interiors of the fixing ring A and the fixing ring B both have threads for connecting with the stirring rod.

[0067] Further preferably, the conical dispersing member is selected from one of the No. 1 conical dispersing member, the No. 2 conical dispersing member, and the No. 3 conical dispersing member. The No. 1 conical dispersing member includes a No. 1 conical dispersing disk, and multiple rows of holes are arranged in a circumferential array on the No. 1 conical dispersing disk. Each row includes multiple through holes evenly spaced along the generatrix direction; the distance between adjacent through holes in each row is 3-6 mm. On its outer side wall, a chute is provided between any two rows of holes; the depth of the chute is 3-5 mm, the width is 2-8 mm, and the angle between the generatrix of the No. 1 conical dispersing disk and the horizontal plane is 5-60°; preferably 15-45°;

[0068] The No. 2 conical dispersing member includes a No. 2 conical dispersing disk, which is an inverted cone. There are multiple rows of holes arranged circumferentially on the No. 2 conical dispersing disk. Each row includes multiple through holes evenly spaced along the generatrix direction. The spacing between adjacent through holes in each row is 8 - 15 mm. And on its inner side wall, there is a rib between any two rows of holes. The height of the rib is 3 - 5 mm, and the width is 2 - 4 mm. The angle between the generatrix of the conical dispersing disk and the horizontal plane is 30 - 45°.

[0069] The No. 3 conical dispersing member includes a No. 3 conical dispersing disk, which is an inverted cone. There are multiple rows of holes arranged circumferentially on the No. 3 conical dispersing disk. Each row includes multiple through holes evenly spaced along the generatrix direction. The spacing between adjacent through holes in each row is 4 - 12 mm. And on its inner side wall, there is a rib between any two rows of holes. The height of the rib is 1.5 - 2.5 mm, and the width is 3 - 6 mm. The angle between the generatrix of the conical dispersing disk and the horizontal plane is 10 - 30°.

[0070] In a preferred embodiment, there are multiple rows of holes arranged circumferentially on the disk surface of the circular dispersing disk. Each row includes multiple through holes evenly spaced along the radial direction. The spacing between adjacent through holes in each row is 5 - 10 mm. And above the disk surface, there is a rib between any two rows of holes. The height of the rib is 3 - 5 mm, and the width is 3 - 8 mm.

[0071] In a preferred embodiment, the stirring paddle is selected from one of stirring paddle A, stirring paddle B, and stirring paddle C. Stirring paddle A is a straight - blade stirring paddle. Stirring paddle B is an inclined - blade stirring paddle, and its blades form an angle of 30° with the horizontal plane. Stirring paddle C is an inclined - blade stirring paddle, and its blades form an angle of - 30° with the horizontal plane.

[0072] In a preferred embodiment, an electromagnetic induction coil surrounds the outside of the composite reaction crucible. Using the principle of electromagnetic induction to quickly increase the temperature and provide electromagnetic stirring, and generating shear force and circulation in the melt through mechanical stirring, which generates a synergistic effect with the electromagnetic stirring provided by the electromagnetic induction coil, making the melt form a complex flow state and further improving the dispersion of the reinforcing particles.

[0073] In a preferred embodiment, the nozzle faces the top surface of the tray.

[0074] In a preferred embodiment, the spraying device further includes a swinging mechanism, and the swinging mechanism is used to swing the nozzle synchronously.

[0075] Beneficial effects

[0076] The present invention combines mechanical stirring (three-dimensional flow field), melt dispersion, in-situ liquid-phase reaction and spray forming process to realize the in-situ generation and uniform dispersion of reinforcement phases, and solves the technical problems such as uneven distribution of reinforcement phases, weak interfacial bonding, coarse particles and insufficient in-situ reaction in the traditional spray forming process. Compared with the prior art, it has at least the following advantages:

[0077] ① Realize the nanocrystallization and uniform distribution of reinforcement phases: Through the synergistic action of melt dispersion spray in-situ reaction and three-dimensional flow field, combined with the ultra-high cooling rate of the atomization process, the solidification interface is strengthened to capture the strengthening particles, and the segregation of the reinforcement phases during solidification is inhibited, ensuring the uniform distribution of nanoscale reinforcement phases inside the matrix.

[0078] ② Strengthen the interfacial bonding: Aiming at the defects of poor interfacial bonding between the reinforcement phase and the matrix in the mechanical mixing method and insufficient bonding strength caused by incomplete in-situ reaction in the in-situ synthesis method, in-situ generated strengthening particles are formed through the synergistic action of melt dispersion spray in-situ reaction + three-dimensional flow field to form coherent / semi-coherent interfaces, effectively improving the interfacial bonding strength between the reinforcement phase and the matrix.

[0079] ③ Improve the process continuity: Aiming at the low efficiency problem caused by the multi-step separation and batch production of "melting → reaction → spray forming" in the prior art, the present invention integrates the whole process of melting-reaction-atomization-deposition to improve the efficiency and process continuity.

[0080] ④ Improve the general applicability: Develop a variety of matrix metals (such as Al, Cu, Mg, etc.) and a variety of reaction alloy systems (such as Al-Ti, Cu-B, etc.), support a variety of in-situ reaction types, including the formation of intermetallic compounds (such as Al-Ti → Al3Ti), the synthesis of ceramic phases (such as Al-B → AlB2), and oxide dispersion strengthening (such as Cu-O → Cu2O → Cu + Al2O3), adapt to multi-variety and small-batch customized production, and have good process universality. Brief Description of the Drawings

[0081] Figure 1 It is a schematic diagram of the overall structure of the preparation device of the present invention. Among them, the reference numerals in the figure: 1, fixator; 2, No. 1 stopper rod; 3, electromagnetic induction coil; 4, electromagnetic induction coil heat insulation layer; 5, first temperature sensor; 5-1, second temperature sensor; 6, heat insulation air gap; 7, quartz sleeve; 8, No. Ⅰ crucible; 9, No. 1 liquid outlet; 10, No. 1 discharge pipe; 11, servo motor; 12, long rod of the stirring rod; 13, disperser; 14, short rod of the stirring rod; 15, stirring paddle; 16, third temperature sensor, 16-1, fourth temperature sensor; 17, No. 3 stopper rod; 18, lower liquid outlet; 19, nozzle; 20, composite reaction crucible; 21, spray chamber; 22, tray; 23, lifting and rotating device.

[0082] Figure 2 3D schematic diagram of the disperser provided by the present invention, where Figure 2 (a) is the No. 1 conical dispersing part; Figure 2 (b) is the No. 2 conical dispersing part; Figure 2 (c) is the No. 3 conical dispersing part; Figure 2 (d) is the circular dispersing part.

[0083] Figure 3 3D schematic diagram of the stirring paddle provided by the present invention, where Figure 3 (a) is stirring paddle A; Figure 3 (b) is stirring paddle B; Figure 3 (c) is stirring paddle C.

[0084] Figure 4 Microstructure morphology diagram of the Al3Ti / TiB2 / Al composite material prepared in Example 1 of the present invention.

[0085] Figure 5 Microstructure morphology diagram of the Al2O3 / Cu composite material prepared in Example 4 of the present invention.

[0086] Figure 6 Microstructure morphology diagram of the HfB2 / Cu composite material prepared in Example 5 of the present invention.

[0087] Figure 7 Microstructure morphology diagram of the AlB2 / Mg composite material prepared in Example 6 of the present invention. Detailed implementation manners

[0088] Referring to Figure 1 , a composite material spray forming device based on in-situ reaction of melt dispersion, comprising: crucible I 8, crucible II 8-1, composite reaction crucible 20, mechanical stirring-melt dispersion device, spray device;

[0089] The composite reaction crucible 20 is located at the center of the device. Its left end is connected to the 1st liquid outlet 9 of the crucible I 8 through the 1st discharge pipe 10, and its right end is connected to the crucible II 8-1 through the 2nd discharge pipe. When the 1st discharge pipe 10 conveys the melt A, it should be avoided that the melt A enters the disperser 13. Therefore, the nozzle of the 1st discharge pipe 10 keeps a safety distance of 5-10 mm from the disperser 13. The horizontal plane of the 2nd discharge pipe should be located above the disperser 13. When the 2nd discharge pipe conveys the melt B, it should be ensured that the melt B completely enters the rotating disperser 13. The distance between its top and the disperser 13 in height is controlled within 10-20 mm to prevent collision with the rotating disperser 13 during the preparation process. Horizontally, the distance between the outlet end of the 2nd discharge pipe and the center of the disperser 13 is controlled within 15-25 mm.

[0090] The No. I crucible 8 is provided with a No. 1 stopper rod 2, and the No. II crucible is provided with a No. 2 stopper rod. The structures of the two are the same. Taking the No. I crucible 8 as an example, the No. 1 stopper rod 2 is connected to a vertical transmission device. The vertical transmission device includes a threaded pipe and a fixator 1. The lifting of the No. 1 stopper rod 2 is controlled by the up and down movement of the fixator 1. The rising and falling actions of the No. 1 stopper rod directly affect the opening and closing as well as the opening degree of the No. 1 liquid outlet 9 in the No. I crucible, thereby affecting the outflow speed of the melt A, and further ensuring the continuity and stability of the output of the melt A during the production process.

[0091] The composite reaction crucible 20, the No. I crucible 8, and the No. II crucible 8-1 are all provided with heat preservation devices. Taking the heat preservation device of the No. I crucible 8 as an example, from the inside to the outside, it includes a heat insulation air gap 6, a quartz sleeve 7, and an electromagnetic induction coil heat preservation layer 4. The heat insulation air gap 6 is filled with asbestos. The electromagnetic induction coil heat preservation layer 4 is composed of an electromagnetic induction coil 3 and asbestos filled in the gap of the electromagnetic induction coil 3, which effectively reduces heat dissipation. The quartz sleeve 7 has both mechanical strength and oxidation resistance.

[0092] In addition, in order to accurately control the temperature of the melt in the No. I crucible 8, the No. II crucible 8-1, and the composite reaction crucible 20, temperature measurement holes are provided on the No. I crucible 8, the No. II crucible 8-1, and the composite reaction crucible 20 for installing temperature sensors. Taking the No. I crucible 8 and the composite reaction crucible 20 as examples, the No. I crucible 8 contains two temperature measurement holes for installing a first temperature sensor 5 located at the lower part of the No. I crucible 8 and a second temperature sensor 5-1 located at the upper part of the No. I crucible, respectively measuring the temperatures of the lower layer and the upper layer of the melt A; the composite reaction crucible 20 also contains two temperature measurement holes for installing a third temperature sensor 16 located at the lower part of the composite reaction crucible 20 and a fourth temperature sensor 16-1 located at the upper part of the composite reaction crucible 20, respectively measuring the temperatures of the lower layer and the upper layer of the composite melt; the first temperature sensor 5, the second temperature sensor 5-1, the third temperature sensor 16, and the fourth temperature sensor 16-1 are all connected to the heating system through wires. The heating system is controlled by a PID program. The temperature sensors feedback the measured temperatures to the heating system, and heating is achieved through the induction coil, with extremely small temperature fluctuations, ensuring process accuracy.

[0093] Three groups of liquid outlets are arranged side by side at intervals at the bottom of the composite reaction crucible 20. Any group of liquid outlets consists of an upper liquid outlet and a lower liquid outlet 18. Any group of liquid outlets is provided with a No. 3 stopper rod 17 perpendicular thereto. The No. 3 stopper rod 17 is connected to a horizontal transmission device through bolts. By controlling the horizontal movement distance, the opening and closing of the liquid outlet and the flow rate of the composite melt are controlled.

[0094] Below the composite reaction crucible 20 is a spraying device: The spraying device includes a spraying chamber 21, a lifting and rotating device 23, a tray 22, and a nozzle 19. The top end of the spraying chamber 21 is connected to the bottom end of the composite reaction crucible 20. There are 3 nozzles 19 arranged in the spraying chamber 21. The 3 nozzles 19 are arranged at intervals along the radial direction of the tray. The 3 nozzles 19 are correspondingly connected to 3 groups of liquid outlets in the composite reaction crucible 20. Among them, the nozzle near the central axis of the tray is the inner ring nozzle, the nozzle far from the central axis of the tray is the outer ring nozzle, and the middle one is the central nozzle. The spraying melt flowing out of the composite reaction crucible 20 is atomized into micron-sized droplets to form a jet under the action of high-pressure protective gas (gas atomization medium), and rapidly solidifies by impacting at a high speed on the circular deposition surface of the tray 22. The tray 22 and the lifting and rotating device 23 have the same vertical central axis. The lifting and rotating device 23 drives the tray 22 to rotate around the central axis and move along the central axis. The nozzle 19 faces the top surface of the tray 22. The nozzle is connected to a swing mechanism and can achieve the effect of synchronous swing during spraying. Under the drive of the swing mechanism to reciprocally swing the nozzle 19 and the drive of the lifting and rotating device 23 to rotate and lift the tray 22, uniform deposition of the metal composite material is achieved.

[0095] The specific structures of the above stopper rod, lifting and rotating device, swing mechanism, etc., as well as the unseen atmosphere protection device and vacuum pumping system are all prior arts and will not be elaborated here. In addition, the materials of the above crucibles, discharge pipes, stirring paddles, and stopper rods are all graphite or refractory materials, and the material of the nozzle needs to be high-temperature resistant and wear-resistant ceramics.

[0096] The mechanical stirring-melt dispersion device consists of: a servo motor 11, a long rod 12 of the stirring rod, a disperser 13, a short rod 14 of the stirring rod, and a stirring paddle 15, which are connected by threads above. In the mechanical stirring-melt dispersion device, the distance between the disperser 13 and the stirring paddle 15 is 40 - 60 mm.

[0097] Among them, the disperser 13 is selected from a conical dispersion part or a circular dispersion part. The conical dispersion part includes a conical dispersion plate. Multiple rows of holes are arranged in a circumferential array on the conical dispersion plate. Each row includes multiple through holes spaced along the generatrix direction; the circular dispersion part includes a circular dispersion plate. Multiple rows of holes are arranged in a circumferential array on the circular dispersion plate. Each row includes multiple through holes spaced along the radial direction.

[0098] On the outer side wall of the conical dispersion plate, there is a chute between any two rows of holes; or on the inner side wall of the conical dispersion plate, there is a rib between any two rows of holes; on the upper surface of the circular dispersion plate, there is a rib between two rows of holes.

[0099] In the conical dispersion plate or the circular dispersion plate, the aperture of any one through hole is 2 - 3 mm, and the distribution density of the through holes is 0.5 - 1.5 pieces / cm 2;

[0100] The thickness of the conical dispersion disc or the circular dispersion disc is 2-9 mm;

[0101] The conical dispersion member further includes a fixing ring A fixed above the conical dispersion disc and coaxial with the conical dispersion disc. The circular dispersion member further includes a fixing ring B fixed above the circular dispersion disc and coaxial with the circular dispersion disc. The outer diameters of the fixing ring A and the fixing ring B are both 15-20 mm, and the interiors of the fixing ring A and the fixing ring B both have threads for connecting with the stirring rod.

[0102] Further, as Figure 2 shown, the disperser 13 is divided into four types, namely the No. 1 conical dispersion member as Figure 2 (a) shown, the No. 2 conical dispersion member as Figure 2 (b) shown, the No. 3 conical dispersion member as Figure 2 (c) shown, and the circular dispersion member as Figure 2 (d) shown. Among them, the No. 1 conical dispersion member includes a No. 1 conical dispersion disc. The No. 1 conical dispersion disc is circumferentially arrayed with multiple rows of holes. Each row includes a plurality of through holes evenly spaced along the generatrix direction; the spacing between adjacent through holes in each row is 3-6 mm. On its outer side wall, a chute is provided between any two rows of holes; the depth of the chute is 3-5 mm, and the width is 2-8 mm. The angle between the generatrix of the No. 1 conical dispersion disc and the horizontal plane is 5-60°; preferably 15-45°;

[0103] The No. 2 conical dispersion member includes a No. 2 conical dispersion disc. The No. 2 conical dispersion disc is an inverted cone. The No. 2 conical dispersion disc is circumferentially arrayed with multiple rows of holes. Each row includes a plurality of through holes evenly spaced along the generatrix direction; the spacing between adjacent through holes in each row is 8-15 mm. And on its inner side wall, a rib is provided between any two rows of holes; the height of the rib is 3-5 mm, and the width is 2-4 mm; the angle between the generatrix of the conical dispersion disc and the horizontal plane is 30-45°;

[0104] The No. 3 conical dispersion member includes a No. 3 conical dispersion disc. The No. 3 conical dispersion disc is an inverted cone. The No. 3 conical dispersion disc is circumferentially arrayed with multiple rows of holes. Each row includes a plurality of through holes evenly spaced along the generatrix direction. The spacing between adjacent through holes in each row is 4-12 mm. And on its inner side wall, a rib is provided between any two rows of holes; the height of the rib is 1.5-2.5 mm, and the width is 3-6 mm; the angle between the generatrix of the conical dispersion disc and the horizontal plane is 10-30°;

[0105] The circumferential array of the circular surface of the circular dispersion disk is provided with multiple rows of holes. Each row includes a plurality of through holes evenly distributed at intervals along the radial direction. The distance between adjacent through holes in each row is 5-10 mm. And above the circular surface, a convex strip is arranged between any two rows of holes. The height of the convex strip is 3-5 mm, and the width is 3-8 mm.

[0106] See Figure 3 , the stirring paddle 15 is divided into three types. The stirring paddle A is as shown in Figure 3 (a), the stirring paddle B is as shown in Figure 3 (b), the stirring paddle C is as shown in Figure 3 (c). Among them, the stirring paddle A is a straight blade type stirring paddle, the stirring paddle B is an inclined blade type stirring paddle, and its blades form an angle of 30° with the horizontal plane. The stirring paddle C is an inclined blade type stirring paddle, and its blades form an angle of -30° with the horizontal plane.

[0107] Example 1

[0108] Preparation of Al3Ti / TiB2 / Al composite material. Mass fraction: the content of Al3Ti is 2%, the content of TiB2 is 1.5%, and the balance is aluminum. Raw materials: Al (99.9%), Al-5B alloy, Al-10Ti alloy. The stirring paddle C and the circular dispersion part are selected.

[0109] In this example, the density of Al3Ti is about 3.5 g / cm 3 , the density of TiB2 is about 4.5 g / cm 3 , the density of the Al-based melt is about 2.7 g / cm 3 , the density of the Al-based melt is less than the densities of Al3Ti and TiB2 particles, and the density difference exceeds 0.3 g / cm 3 , so the stirring paddle C is selected. At a temperature above 700 °C, the viscosity of the melt B (i.e., the Al-B melt) > 10 mPa·s, and the wetting angle between the melt B (i.e., the Al-B melt) and graphite > 120°. Therefore, the circular dispersion part is selected. In the circular dispersion part, the aperture of the through hole is 3 mm, and the distribution density of the through holes is 0.7 pieces / cm 2 , the distance between adjacent through holes in each row is 8 mm. And above the circular surface, a convex strip is arranged between any two rows of holes. The height of the convex strip is 3 mm, and the width is 6 mm; the maximum diameter of the dispersion disk is 62 mm; the distance between the stirring paddle C and the lowest point of the circular dispersion part is 45 mm.

[0110] Specifically, it is implemented according to the following steps:

[0111] Step 1: Place the Al-Ti raw material and the Al-B raw material in the No. I and No. II crucibles respectively according to the ratio, and ensure that the mass ratio of Ti:B is 5:1.

[0112] Step 2: Heat the crucible No.Ⅰ to 760°C (the melting point of Al-Ti is 690°C) and hold for 8 minutes; heat the crucible No.Ⅱ to 760°C (the melting point of Al-B is 680°C) and hold for 8 minutes.

[0113] Step 3: During the melting of the raw materials, heat the composite reaction crucible to 760°C (the melting point of the composite melt is 670°C) and hold for 10 min. During the heating and holding processes, an argon protective atmosphere with a purity of more than 99.9% is introduced into all crucibles throughout the process (the flow rate is 30 L / h).

[0114] Step 4: Start the servo motor to drive the mechanical stirring-melt dispersion spraying device to rotate, and adjust the rotation speed to 100 r / min.

[0115] Step 5: Control the stopper in the crucible No.Ⅰ to rise and transfer all the Al-Ti melt in the crucible No.Ⅰ to the composite reaction crucible.

[0116] Step 6: Inject the Al-B melt in the crucible No.Ⅱ into the circular dispersing part at a flow rate of 10 cm 3 / s. The Al-B melt is dispersed and sprayed into fine droplets, and under the stirring action, it is fully mixed with the Al-Ti melt, and an in-situ reaction occurs to generate Al3Ti and TiB2 strengthening particles, forming a composite melt. The total time required for melt dispersion spraying and the in-situ reaction of the two melts is about 100 s. During the in-situ reaction process, control the depth of the stirring paddle inserted into the melt to be 50% of the total depth of the melt.

[0117] Step 7: Adjust the rotation speed of the servo motor to 220 r / min, and at the same time perform electromagnetic stirring, control the frequency of the electromagnetic stirring to be 70Hz, and the magnetic field strength to be 0.25T; at the same time, raise the temperature of the composite reaction crucible to 850°C (the superheat is 180°C) and hold for 10 min.

[0118] Step 8: Adjust the pressure of the atomizing medium (argon) to 0.5 MPa, and then pull the stopper No.3 through the horizontal transmission device to open the three liquid outlets, and the composite melt flows out through the liquid outlets at a speed of 0.3 cm 3 / s; at the same time, open the atomizing gas valve and the lifting and rotating device, and use 3 nozzles to atomize and spray the melt to form a particle spray stream, and make the particle spray stream deposit on the tray at a high speed.

[0119] In Step 8, the spraying angle of the outer ring nozzle is 50°, the spraying angle of the inner ring nozzle is 10°, and the spraying angle of the middle nozzle is 30°; the temperature of the gas atomizing medium is 70°C, the gas flow rate is 30 L / min, the rotation speed of the tray is 50 rpm, the descending speed of the tray is 2 mm / s, the initial receiving distance of the tray is 150 mm, and the final receiving distance is 800 mm.

[0120] The obtained ingot has an Al3Ti content of 2%, a TiB2 content of 1.5%, an average particle size of the strengthening phase of 137 nm, a relative density of 99.50%, and a hardness of 390 HV; as Figure 4 , the reinforcing phases (Al3Ti, TiB2) are uniformly distributed inside the matrix without macroscopic segregation or agglomeration.

[0121] Example 2

[0122] Other conditions are the same as those in Example 1, but stirring paddle C and the No. 2 conical dispersing member are used. The pore diameters of the through holes in the No. 2 conical dispersing member are all 3 mm, and the distribution density of the through holes is 0.8 per cm 2 , the distance between adjacent through holes in each row is 10 mm, the height of the rib is 3 mm, the width is 4 mm, and the angle between the generatrix of the conical dispersing disk and the horizontal plane is 30°; the maximum diameter of the dispersing disk is 60 mm. In the mechanical stirring-melt dispersion device, the distance between stirring paddle C and the lowest point of the No. 2 conical dispersing member is 45 mm;

[0123] The obtained ingot has an Al3Ti content of 1.9%, a TiB2 content of 1.6%, an average particle size of the strengthening phase of 152 nm (15 nm larger than that in Example 1), a relative density of 98.40% (1.1% lower than that in Example 1), and a hardness of 372 HV (18 HV lower than that in Example 1).

[0124] Example 3

[0125] Other conditions are the same as those in Example 1. Only after the in-situ reaction is completed, during the continuous mechanical stirring process, the rotation speed of the mechanical stirring-melt dispersion device is controlled to cycle periodically as 200 r / min → 250 r / min → 300 r / min → 200 r / min → 250 r / min → 300 r / min, and each rotation speed is maintained for 8 s.

[0126] The obtained ingot has an Al3Ti content of 2.0%, a TiB2 content of 1.6%, an average particle size of the strengthening phase of 115 nm (22 nm smaller than that in Example 1), a relative density of 99.80% (0.3% higher than that in Example 1), and a hardness of 403 HV (13 HV higher than that in Example 1).

[0127] Example 4

[0128] Preparation of Al2O3 / Cu composite material. Mass fraction: the Al2O3 content is 2.5%, and the balance is Cu. Raw materials: Cu (99.9%), Cu2O powder, Al (99.9%). Stirring paddle B and the No. 3 conical dispersing member are selected.

[0129] In this example, the density of the Cu-based melt is about 8.96 g / cm3 , the density of Al2O3 particles is 3.95 g / cm³, the density of the Cu-based melt is much greater than that of the Al2O3 particles, and the density difference is 5.01 g / cm 3 , stirring paddle B is selected; at temperatures above 1100 °C, the viscosity of the Cu-Al melt < 10 mPa·s, and the wetting angle between the Cu-Al melt and graphite > 120°, so the No. 3 conical dispersing member is selected; the aperture of the through holes in the No. 3 conical dispersing member used is 2.5 mm, and the distribution density of the through holes is 1 per cm 2 , the distance between adjacent through holes in each row is 8 mm, the height of the rib is 2 mm, and the width is 6 mm; the angle between the generatrix of the conical dispersing disk and the horizontal plane is 25°; the maximum diameter of the dispersing disk is 60 mm. In the mechanical stirring-melt dispersing device, the distance between the stirring paddle B and the lowest point of the No. 3 conical dispersing member is 50 mm.

[0130] Specifically, it is implemented according to the following steps:

[0131] Step 1: Place Cu raw materials and Cu-Al raw materials in crucibles I and II respectively according to the ratio, and place Cu2O powder in the composite reaction crucible. The mass ratio of Cu2O:Al is ensured to be 8:1.

[0132] Step 2: Heat crucible I to 1160 °C (the melting point of Cu is about 1083 °C) and keep it warm for 10 minutes; heat crucible II to 1160 °C (the melting point of Cu-Al is 1085 °C) and keep it warm for 10 minutes.

[0133] Step 3: During the heating and melting of the raw materials, heat the composite reaction crucible to 1160 °C (the melting point of the composite melt is 1085 °C) and keep it warm for 10 min. During the heating and insulation processes, an argon protective atmosphere with a purity of more than 99.9% (flow rate: 40 L / h) is introduced into all crucibles throughout the process.

[0134] Step 4: Start the servo motor to drive the mechanical stirring-melt dispersing and spraying device to rotate, and adjust the rotation speed to 120 r / min.

[0135] Step 5: Control the stopper in crucible I to rise, and transfer all the Cu melt in crucible I to the composite reaction crucible to mix with the Cu2O powder.

[0136] Step 6: Transfer the Cu-Al melt in crucible II at 7 cm 3The flow rate of / s is injected into the No. 3 conical disperser. The Cu-Al melt is dispersed and sprayed into fine droplets, and fully mixed with the Cu-Cu2O melt under stirring, and in-situ reaction occurs to generate Al2O3 strengthening particles, forming a composite melt. The total time required for the melt dispersion spraying and the in-situ reaction of the two melts is about 60 s. During the in-situ reaction process, the depth of the stirring paddle inserted into the melt is controlled to be 45% of the total depth of the melt.

[0137] Step 7: Adjust the rotational speed of the servo motor to 250 r / min, and at the same time carry out electromagnetic stirring, control the frequency of electromagnetic stirring to be 75 Hz, and the magnetic field strength to be 0.3 T; at the same time, raise the temperature of the composite reaction crucible to 1300 °C (superheat degree is 215 °C), and keep it warm for 10 min.

[0138] Step 8: Adjust the pressure of the atomizing medium (argon) to 0.8 MPa, and then pull the No. 3 stopper rod through the horizontal transmission device to open the three liquid outlets. The composite melt flows out of the liquid outlets at a speed of 0.4 cm 3 / s; at the same time, open the atomizing gas valve and the lifting and rotating device, use the nozzle to atomize and spray the melt to form a particle spray stream, and make the particle spray stream deposit on the tray at a high speed.

[0139] In step 8, the spraying angle of the outer ring nozzle is 45°, the spraying angle of the inner ring nozzle is 5°, and the spraying angle of the middle nozzle is 40°; the temperature of the gas atomizing medium is 80 °C, the gas flow rate is 40 L / min, the rotational speed of the tray is 40 rpm, the descending speed of the tray is 1.5 mm / s, the initial receiving distance of the tray is 180 mm, and the final receiving distance is 780 mm.

[0140] The mass fraction of Al2O3 in the obtained ingot blank is 2.5%, the average particle size of the strengthening phase is 142 nm, the relative density is 99.90%, and the hardness is 320 HV; as Figure 5 , the reinforcing phase (Al2O3) is uniformly distributed inside the matrix, without macroscopic segregation or agglomeration phenomenon.

[0141] Comparative Example 1

[0142] Other conditions are the same as those in Example 4, only the holding temperature in steps 2 and 3 is changed to 1300 °C.

[0143] The mass fraction of Al2O3 in the obtained ingot blank is 2.5%, the average particle size of the strengthening phase is 193 nm (51 nm larger than that in Example 4), the relative density is 99.0% (0.9% lower than that in Example 4), and the hardness is 290 HV (30 HV lower than that in Example 4).

[0144] Comparative Example 2:

[0145] Other conditions are the same as in Example 4, except that the heat preservation temperature in Step 7 is changed to 1150 °C (superheat degree 65 °C).

[0146] The mass fraction of Al2O3 in the obtained ingot blank is 2.5%, the average particle size of the strengthening phase is 148 nm, the relative density is 90.20% (9.7% lower than that in Example 4), and the hardness is 280 HV (40 HV lower than that in Example 4).

[0147] Example 5

[0148] Preparation of HfB2 / Cu composite material. Mass fraction: the content of HfB2 is 2%, and the balance is Cu. Raw materials: Cu (99.9%), Cu-4B alloy, Cu-8Hf alloy. Stirring paddle C and No. 1 conical dispersion part are selected.

[0149] In this example, the density of the Cu-based melt is about 8.96 g / cm 3 , and the density of the HfB2 particles is 10.5 g / cm 3 . Since the density of the Cu-based melt is less than that of the HfB2 particles, and the density difference is 1.54 g / cm 3 , stirring paddle C is selected; at temperatures above 1200 °C, the viscosity of the Cu-Hf melt > 10 mPa·s, and the wetting angle between the Cu-Hf melt and graphite < 120°, so No. 1 conical dispersion part is selected; the aperture of the through holes in the used No. 1 conical dispersion part is 3 mm, and the distribution density of the through holes is 0.8 per cm 2 . The distance between adjacent through holes in each row is 5 mm, the depth of the chute is 4 mm, the width is 8 mm, and the angle between the generatrix of the No. 1 conical dispersion disk and the horizontal plane is 20°; the maximum diameter of the dispersion disk is 60 mm. In the mechanical stirring-melt dispersion device, the distance between the stirring paddle C and the lowest point of the No. 1 conical dispersion part is 40 mm.

[0150] The specific implementation steps are as follows:

[0151] Step 1: Place the Cu-B raw material and the Cu-Hf raw material in the No. I and No. II crucibles respectively according to the ratio. The molar ratio of Hf:B is ensured to be 1:2.

[0152] Step 2: Heat the No. I crucible to 1200 °C (the melting point of Cu-B is 1080 °C) and keep it warm for 10 minutes; heat the No. II crucible to 1200 °C (the melting point of Cu-Hf is 1120 °C) and keep it warm for 10 minutes.

[0153] Step 3: During the heating and melting of the raw materials, heat the composite reaction crucible to 1180 °C (the melting point of the composite melt is 1085 °C) and keep it warm for 10 min. During the heating and heat preservation processes, an argon protection atmosphere with a purity of more than 99.9% (flow rate 30 L / h) is introduced into all crucibles throughout the process.

[0154] Step 4: Turn on the servo motor to drive the mechanical stirring-melt dispersion device to rotate, and adjust the speed to 150 r / min.

[0155] Step 5: Control the stopper rod in crucible No. 1 to rise, and transfer all the Cu-B melt in crucible No. 1 to the composite reaction crucible.

[0156] Step 6: Heat the Cu-Hf melt in crucible No. Ⅱ at 12 cm 3 / s is injected into the conical dispersion piece No. 1. The Cu-Hf melt is dispersed into fine droplets, which are fully mixed with the Cu-B melt under stirring, and react in situ to generate HfB2 strengthening particles to form a composite melt. The melt dispersion and the in situ reaction of the two melts take about 60 s in total. During the in situ reaction, the depth of the stirring paddle into the melt is controlled to be 45% of the total depth of the melt.

[0157] Step 7: Adjust the speed of the servo motor to 270 r / min, and perform electromagnetic stirring at the same time. The frequency of electromagnetic stirring is controlled to 85 Hz and the magnetic field strength is 0.2 T. At the same time, the temperature of the composite reaction crucible is raised to 1300°C (superheat is 215°C) and kept warm for 10 minutes.

[0158] Step 8: Adjust the atomizing medium (argon) pressure to 0.6 MPa, then pull the No. 3 stopper rod through the horizontal transmission device to open the three liquid outlets, and the composite melt flows through the liquid outlet at a speed of 0.2 cm 3 / s; at the same time, the atomizing gas valve and the lifting and rotating device are opened, and the melt is sprayed by the nozzle to form a particle jet flow, and the particle jet flow is deposited on the tray at a high speed.

[0159] In step 8, the spray angle of the outer ring nozzle is 50°, the spray angle of the inner ring nozzle is 0°, and the spray angle of the middle nozzle is 45°; the temperature of the atomizing medium is 50°C, the gas flow rate is 30 L / min, the tray rotation speed is 30 rpm, the tray descending speed is 1 mm / s, the initial receiving distance of the tray is 120 mm, and the final receiving distance is 600 mm.

[0160] The mass fraction of HfB2 in the obtained ingot is 2%, the average particle size of the strengthening phase is 142 nm, the density is 99.90%, and the hardness is 240 HV. Figure 6 The reinforcement phase is evenly distributed inside the matrix without macroscopic segregation or agglomeration.

[0161] Comparative Example 3

[0162] The other conditions are the same as those in Example 5, except that the dispersion member is not installed.

[0163] The mass fraction of HfB2 in the obtained ingot blank is 2%, the average particle size of the strengthening phase is 219 nm (77 nm larger than that in Example 5), the relative density is 98.40%, and the hardness is 210 HV (30 HV lower than that in Example 5).

[0164] Comparative Example 4

[0165] Other conditions are the same as those in Example 5, except that the temperature of the gas atomization medium is changed to -50 °C.

[0166] The mass fraction of HfB2 in the obtained ingot blank is 2%, the average particle size of the strengthening phase is 145 nm, the relative density is 88.70% (10.1% lower than that in Example 5), and the hardness is 200 HV (40 HV lower than that in Example 5).

[0167] Example 6

[0168] Preparation of AlB2 / Mg composite material. The content of AlB2 is 2.5%, and the rest is Mg. Raw materials: pure Mg, pure Al, and pure B. In this example, stirring paddle C and No. 2 conical dispersion part are selected.

[0169] In this example, the density of AlB2 particles is about 3.16 g / cm 3 , and the density of the Mg-based melt is about 1.58 g / cm 3 , the density of the Mg-based melt is less than that of AlB2 particles, and the density difference exceeds 0.3 g / cm 3 , so stirring paddle C is selected. At a temperature above 650 °C, the viscosity of the Mg-Al melt < 10 mPa·s, and the wetting angle between the Mg-Al melt and graphite < 120°, so No. 2 melt dispersion part is selected.

[0170] The aperture of the through holes in the No. 2 conical dispersion part is 3 mm, and the distribution density of the through holes is 0.8 per cm 2 , the distance between adjacent through holes in each row is 8 mm, the height of the rib is 3 mm, and the width is 2 mm; the angle between the generatrix of the conical dispersion disk and the horizontal plane is 45°; the maximum diameter of the dispersion disk is 60 mm. In the mechanical stirring-melt dispersion device, the distance between the stirring paddle C and the No. 2 conical dispersion part is 40 mm.

[0171] Specifically, it is implemented according to the following steps:

[0172] Step 1: Place the pure Mg and pure B raw materials in crucible No. I in proportion, and place the pure Mg and pure Al raw materials in crucible No. II in proportion. Ensure that the molar ratio of B:Al is 2:1.

[0173] Step 2: Heat the crucible No.Ⅰ to 730 °C (the melting point of Mg-B is 650 °C) and hold for 10 minutes; heat the crucible No.Ⅱ to 730 °C (the melting point of Mg-Al is 660 °C) and hold for 10 minutes.

[0174] Step 3: During the heating and melting of the raw materials, heat the composite reaction crucible to 730 °C (the melting point of the composite melt is 650 °C) and hold for 10 min. During the heating and holding process, an argon protective atmosphere with a purity of more than 99.9% (flow rate: 45 L / h) is introduced into all crucibles throughout the process.

[0175] Step 4: Turn on the servo motor to drive the mechanical stirring-melt dispersion device to rotate, and adjust the rotation speed to 150 r / min.

[0176] Step 5: Control the stopper rod in the crucible No.Ⅰ to rise, and transfer all the Mg-B melt in the crucible No.Ⅰ to the composite reaction crucible.

[0177] Step 6: Inject the Mg-Al melt in the crucible No.Ⅱ into the No.2 conical dispersion part at a rate of 15 cm 3 / s. The Mg-Al melt is dispersed into fine droplets and fully mixed with the Mg-B melt under the stirring action, and an in-situ reaction occurs to generate AlB2 strengthening particles, forming a composite melt. The total time required for melt dispersion and the in-situ reaction of the two melts is about 60 s. During the in-situ reaction process, control the depth of the stirring paddle inserted into the melt to be 50% of the total depth of the melt.

[0178] Step 7: Adjust the rotation speed of the servo motor to 200 r / min, and at the same time perform electromagnetic stirring, control the frequency of the electromagnetic stirring to be 90 Hz, and the magnetic field strength to be 0.3 T; at the same time, raise the temperature of the composite reaction crucible to 820 °C (superheat: 170 °C) and hold for 10 min.

[0179] Step 8: Adjust the pressure of the atomizing medium (argon) to 1 MPa, and then use the horizontal transmission device to pull the No.3 stopper rod to open the three liquid outlets. The composite melt flows out of the liquid outlets at a speed of 0.3 cm 3 / s; at the same time, open the atomizing gas valve and the lifting and rotating device, and use the nozzle to atomize and spray the melt to form a particle spray stream, and make the particle spray stream deposit on the tray at a high speed.

[0180] In Step 8, the spraying angle of the outer ring nozzle is 50°, the spraying angle of the inner ring nozzle is 10°, and the spraying angle of the middle nozzle is 40°; the temperature of the gas atomizing medium is 30 °C, the gas flow rate is 30 L / min, the rotation speed of the tray is 35 rpm, the descending speed of the tray is 0.7 mm / s, the initial receiving distance of the tray is 150 mm, and the final receiving distance is 700 mm.

[0181] The mass fraction of AlB2 in the obtained ingot blank is 2.5%, the average grain size of the strengthening phase is 129 nm, the relative density is 99.90%, and the hardness is 275 HV. As Figure 7 , the reinforcing phase (AlB2) is evenly distributed inside the matrix without macroscopic segregation or agglomeration.

[0182] Comparative Example 5:

[0183] Other conditions are the same as those in Example 6, except that the pressure of the atomizing medium (argon) in Step 8 is changed to 2 MPa.

[0184] The mass fraction of AlB2 in the obtained ingot blank is 2.5%, the average grain size of the strengthening phase is 135 nm, the relative density is 91.40% (8.5% lower than that in Example 6), and the hardness is 210 HV (65 HV lower than that in Example 6). During the preparation process, the melt splashes severely.

Claims

1. A method for spray forming a composite material based on in-situ reaction of melt dispersion, characterized in that: Start the mechanical stirring-melt dispersion device in the composite reaction crucible containing melt A to make it rotate, and then flow melt B in crucible II into the disperser through the No. 2 discharge pipe. The melt B is dispersed into liquid droplets by the disperser under rotation and dropped into melt A. Under the synergistic action of mechanical stirring, an in-situ reaction occurs with melt A to obtain a composite melt containing in-situ strengthening particles. After the in-situ reaction is completed, the temperature is raised, and mechanical stirring continues to obtain a spray melt. Then, the spray melt flows into the corresponding 3 nozzles through 3 lower liquid outlets arranged side by side at intervals at the bottom of the composite reaction crucible. The spray melt is atomized by an atomizing medium to form a jet and deposited onto the tray to obtain the composite material; The viscosity of melt A is higher than that of melt B; The mechanical stirring-melt dispersion device includes a stirring rod, a stirring paddle fixed at the bottom of the stirring rod, and a disperser fixed on the stirring rod above the stirring paddle. The disperser has a porous structure; The 3 nozzles are arranged at intervals along the radial direction of the tray; the nozzle close to the central axis of the tray is the inner ring nozzle, the nozzle far from the central axis of the tray is the outer ring nozzle, and the middle one is the central nozzle; The superheat degree of the spray melt is 150-300°C; The flow rate of any lower liquid outlet is 0.1~0.5 cm 3 / s; The spraying angle of the outer ring nozzle is 30-50°, the spraying angle of the inner ring nozzle is 0-20°, and the spraying angle of the middle nozzle is 0-50°; The temperature of the atomizing medium is 20°C-100°C, the pressure of the atomizing medium is 0.5-1 MPa, and the flow rate of the atomizing medium is 20-50 L / min; The rotation speed of the tray is 30-60 rpm, the lifting speed is 0.5-7 mm / s, and the receiving distance is 100-900 mm.

2. The composite material spray forming method based on in-situ reaction of melt dispersion according to claim 1, wherein: Weigh the corresponding raw materials according to the composition of alloy A, place all the raw materials of alloy A in crucible I for heating to obtain melt A, and then flow melt A into the preheated and heat-insulated composite reaction crucible through the No. 1 discharge pipe. Or place a part of the raw materials of alloy A in crucible I for heating to obtain melt A1, place another part of the raw materials of alloy A in the composite reaction crucible for heating to obtain melt A2, and then flow melt A1 into the composite reaction crucible through the No. 1 discharge pipe to mix with melt A2 to form melt A. Weigh the corresponding raw materials according to the composition of alloy B and place them in crucible II for heating to obtain melt B; The flow rate of the melt B flowing into the disperser through the No. 2 discharge pipe is 5 - 15 cm 3 / s; The height spacing between the No. 2 discharge pipe and the top of the disperser is controlled within 10-20 mm. Horizontally, the distance between the outlet end of the No. 2 discharge pipe and the center of the disperser is controlled within 15-25 mm; During the in-situ reaction process, control the temperature difference between the upper and lower layers of melt A and melt B ≤ 20°C; During the in-situ reaction process, the temperature of melt B is the melting point of alloy B + 50-200°C, and the superheat degree of the composite melt is 50-100°C.

3. A composite material spray forming method based on in-situ reaction of melt dispersion according to claim 1 or 2, characterized in that: In the mechanical stirring-melt dispersion device, the distance between the disperser and the stirring paddle is 40-60 mm; during the in-situ reaction process, by moving the mechanical stirring-melt dispersion device up and down, control the depth of the stirring paddle extending into the melt to be 40-60% of the total depth of the melt, and the distance from the lowest end of the disperser to the liquid surface is controlled within 25-50 mm; The disperser is selected from a conical dispersing member or a circular dispersing member. The conical dispersing member includes a conical dispersing disk, and multiple rows of holes are arranged in a circumferential array on the conical dispersing disk. Each row includes multiple through holes that are spaced apart along the generatrix direction; the circular dispersing member includes a circular dispersing disk, and multiple rows of holes are arranged in a circumferential array on the circular dispersing disk. Each row includes multiple through holes that are spaced apart along the radial direction; On the outer side wall of the conical dispersing disk, a chute is provided between any two rows of holes; or on the inner side wall of the conical dispersing disk, a rib is provided between any two rows of holes; on the upper surface of the circular dispersing disk, a rib is provided between two rows of holes; Among the conical dispersion disc or circular dispersion disc, the aperture of any through hole is 2-3 mm, and the distribution density of the through holes is 0.5-1.5 pieces / cm 2 ; The thickness of the conical dispersing disk or the circular dispersing disk is 2-9 mm.

4. A composite material spray forming method based on in-situ reaction of melt dispersion according to claim 3, characterized in that: The conical dispersing member is selected from one of the No. 1 conical dispersing member, the No. 2 conical dispersing member, and the No. 3 conical dispersing member. The No. 1 conical dispersing member includes a No. 1 conical dispersing disk, and multiple rows of holes are arranged in a circumferential array on the No. 1 conical dispersing disk. Each row includes multiple through holes that are evenly spaced along the generatrix direction; the distance between adjacent through holes in each row is 3-6 mm. On its outer side wall, a chute is provided between any two rows of holes; the depth of the chute is 3-5 mm, and the width is 2-8 mm. The angle between the generatrix of the No. 1 conical dispersing disk and the horizontal plane is 5-60°; The No. 2 conical dispersing member includes a No. 2 conical dispersing disk. The No. 2 conical dispersing disk is an inverted cone. Multiple rows of holes are arranged in a circumferential array on the No. 2 conical dispersing disk. Each row includes multiple through holes that are evenly spaced along the generatrix direction; the distance between adjacent through holes in each row is 8-15 mm. On its inner side wall, a rib is provided between any two rows of holes; the height of the rib is 3-5 mm, and the width is 2-4 mm; the angle between the generatrix of the conical dispersing disk and the horizontal plane is 30-45°; The No. 3 conical dispersing member includes a No. 3 conical dispersing disk. The No. 3 conical dispersing disk is an inverted cone. Multiple rows of holes are arranged in a circumferential array on the No. 3 conical dispersing disk. Each row includes multiple through holes that are evenly spaced along the generatrix direction. The distance between adjacent through holes in each row is 4-12 mm. On its inner side wall, a rib is provided between any two rows of holes; the height of the rib is 1.5-2.5 mm, and the width is 3-6 mm; the angle between the generatrix of the conical dispersing disk and the horizontal plane is 10-30°; Multiple rows of holes are arranged in a circumferential array on the disk surface of the circular dispersing disk. Each row includes multiple through holes that are evenly spaced along the radial direction. The distance between adjacent through holes in each row is 5-10 mm. Above the disk surface, a rib is provided between any two rows of holes. The height of the rib is 3-5 mm, and the width is 3-8 mm; The material of the disperser is graphite. When the melt viscosity of melt B < 10 mPa·s and the wetting angle between melt B and graphite < 120°, the disperser is selected from the No. 2 conical dispersing member. When the melt viscosity of melt B > 10 mPa·s and the wetting angle between melt B and graphite < 120°, the disperser is selected from the No. 1 conical dispersing member. When the melt viscosity of melt B < 10 mPa·s and the wetting angle between melt B and graphite > 120°, the disperser is selected from the No. 3 conical dispersing member. When the melt viscosity of melt B > 10 mPa·s and the wetting angle between melt B and graphite > 120°, the disperser is selected from the circular dispersing member.

5. A composite material spray forming method based on in-situ reaction of melt dispersion according to claim 1 or 2, characterized in that: The stirring paddle is selected from one of stirring paddle A, stirring paddle B, and stirring paddle C. Stirring paddle A is a straight blade stirring paddle. Stirring paddle B is an inclined blade stirring paddle, and its blades form an angle of 30°C with the horizontal plane. Stirring paddle C is an inclined blade stirring paddle, and its blades form an angle of -30°C with the horizontal plane; When the density difference between the composite melt and the in-situ strengthening particles does not exceed 0.3 g / cm 3 , the stirring paddle is selected from stirring paddle A. When the density difference between the composite melt and the in-situ strengthening particles exceeds 0.3 g / cm 3 , and the density of the composite melt is greater than that of the in-situ strengthening particles, the stirring paddle is selected from stirring paddle B. When the density difference between the composite melt and the in-situ strengthening particles exceeds 0.3 g / cm 3 , and the density of the composite melt is less than that of the in-situ strengthening particles, the stirring paddle is selected from stirring paddle C; During the in-situ reaction process, the rotation speed of the mechanical stirring-melt dispersion device is 100 - 150 r / min; After the in-situ reaction is completed, other alloy raw materials are continuously added to the composite melt; After the in-situ reaction is completed, the temperature is raised, and mechanical stirring is continued for 5 - 10 min to obtain a spray melt, and then the spray melt is flowed into a nozzle, and the spray melt is atomized by an air atomizing medium to form a jet and deposited into a tray to obtain the composite material; During the process of continuously performing mechanical stirring to obtain the spray melt and during the deposition process, the rotation speed of the mechanical stirring-melt dispersion device is controlled to be 200 - 300 r / min, and at the same time, electromagnetic stirring is performed, and the frequency of the electromagnetic stirring is controlled to be 60 - 90 Hz, and the magnetic field intensity is 0.2 - 0.3 T.

6. A method for spray forming a composite material based on in-situ reaction of melt dispersion according to claim 5, characterized in that: During the process of continuously performing mechanical stirring to obtain the spray melt and during the deposition process, the rotation speed of the mechanical stirring-melt dispersion device is controlled to cycle and fluctuate at 200 - 230 r / min, 230 - 270 r / min, and 270 - 300 r / min, and the fluctuation period is 5 - 8 s.

7. A composite material spray forming device based on in-situ reaction of melt dispersion, characterized in that: Including: Crucible No. I, Crucible No. II, composite reaction crucible, mechanical stirring-melt dispersion device, spraying device; Crucible No. I is communicated with the composite reaction crucible through a No. 1 discharge pipe, and Crucible No. II is communicated with the composite reaction crucible through a No. 2 discharge pipe; The composite reaction crucible is provided with 3 groups of liquid outlets arranged side by side at intervals. Any group of liquid outlets consists of an upper liquid outlet and a lower liquid outlet. Any group of liquid outlets is provided with a No. 3 stopper rod perpendicular to it, and the No. 3 stopper rod is connected to the horizontal transmission device through a bolt; The mechanical stirring-melt dispersion device penetrates through the top center of the composite reaction crucible and extends into the interior of the composite reaction crucible; the mechanical stirring-melt dispersion device includes a stirring rod, a stirring paddle fixed to the bottom of the stirring rod, and a disperser fixed on the stirring rod above the stirring paddle; the disperser is a porous structure for dispersing the melt melted in Crucible No. II into droplets; The injection device includes an injection chamber, three nozzles, a lifting and rotating device, and a tray; the top of the injection chamber is connected to the composite reaction crucible, the three nozzles, the lifting and rotating device, and the tray are all arranged in the injection chamber, the three nozzles are arranged at intervals along the radial direction of the tray, and the three nozzles are correspondingly connected to three groups of liquid outlets in the composite reaction crucible; among them, the nozzle close to the central axis of the tray is the inner ring nozzle, the nozzle far from the central axis of the tray is the outer ring nozzle, and the middle one is the central nozzle; the three nozzles are used to atomize the injection melt flowing out of the liquid outlet of the composite reaction crucible to form a jet and deposit it on the top surface of the tray, the lifting and rotating device and the tray have the same vertical central axis, and the lifting and rotating device drives the tray to rotate around the central axis and move up and down along the central axis.

8. The composite material spray forming device based on in-situ reaction of melt dispersion according to claim 7, characterized in that: The No. I crucible is provided with a No. 1 stopper rod, the No. II crucible is provided with a No. 2 stopper rod, and the No. 1 stopper rod and the No. 2 stopper rod are respectively connected to the vertical transmission device; The mechanical stirring-melt dispersion device further includes a servo motor and a planetary gear reducer. The servo motor is located outside the composite reaction crucible and is used to drive the stirring paddle and the disperser to rotate, and the rotation speed range is 0-1000 r / min; The stirring rod in the mechanical stirring-melt dispersion device is composed of a long rod and a short rod connected by threads from top to bottom; In the mechanical stirring-melt dispersion device, the distance between the disperser and the stirring paddle is 40-60 mm; The disperser is selected from a conical dispersing member or a circular dispersing member. The conical dispersing member includes a conical dispersing disc, and multiple rows of holes are arranged in a circumferential array on the conical dispersing disc. Each row includes multiple through holes spaced along the generatrix direction; the circular dispersing member includes a circular dispersing disc, and multiple rows of holes are arranged in a circumferential array on the circular dispersing disc. Each row includes multiple through holes spaced along the radial direction; On the outer side wall of the conical dispersing disc, a chute is arranged between any two rows of holes; or on the inner side wall of the conical dispersing disc, a rib is arranged between any two rows of holes; on the upper surface of the circular dispersing disc, a rib is arranged between two rows of holes; Among the conical dispersion disc or the circular dispersion disc, the aperture of any through hole is 2-3 mm, and the distribution density of the through holes is 0.5-1.5 per cm 2 ; The thickness of the conical dispersing disc or the circular dispersing disc is 2-9 mm; The conical dispersing member further includes a fixing ring A fixed above the conical dispersing disc and coaxial with the conical dispersing disc. The circular dispersing member further includes a fixing ring B fixed above the circular dispersing disc and coaxial with the circular dispersing disc. The outer diameters of the fixing ring A and the fixing ring B are both 15-20 mm, and the interiors of the fixing ring A and the fixing ring B both have threads for connecting with the stirring rod.

9. The composite material spray forming device based on in-situ reaction of melt dispersion according to claim 8, wherein: The conical dispersing member is selected from one of the No. 1 conical dispersing member, the No. 2 conical dispersing member, and the No. 3 conical dispersing member. The No. 1 conical dispersing member includes a No. 1 conical dispersing disc, and multiple rows of holes are arranged in a circumferential array on the No. 1 conical dispersing disc. Each row includes multiple through holes evenly spaced along the generatrix direction; the distance between adjacent through holes in each row is 3-6 mm. On its outer side wall, a chute is arranged between any two rows of holes; the depth of the chute is 3-5 mm, the width is 2-8 mm, and the angle between the generatrix of the No. 1 conical dispersing disc and the horizontal plane is 5-60°; The No. 2 conical dispersing member includes a No. 2 conical dispersing disk, which is an inverted cone. There are multiple rows of holes arranged circumferentially on the No. 2 conical dispersing disk. Each row includes multiple through holes evenly spaced along the generatrix direction. The distance between adjacent through holes in each row is 8 - 15 mm. And on its inner side wall, there is a rib provided between any two rows of holes. The height of the rib is 3 - 5 mm and the width is 2 - 4 mm. The angle between the generatrix of the conical dispersing disk and the horizontal plane is 30 - 45°; The No. 3 conical dispersing member includes a No. 3 conical dispersing disk, which is an inverted cone. There are multiple rows of holes arranged circumferentially on the No. 3 conical dispersing disk. Each row includes multiple through holes evenly spaced along the generatrix direction. The distance between adjacent through holes in each row is 4 - 12 mm. And on its inner side wall, there is a rib provided between any two rows of holes. The height of the rib is 1.5 - 2.5 mm and the width is 3 - 6 mm. The angle between the generatrix of the conical dispersing disk and the horizontal plane is 10 - 30°; There are multiple rows of holes arranged circumferentially on the disk surface of the circular dispersing disk. Each row includes multiple through holes evenly spaced along the radial direction. The distance between adjacent through holes in each row is 5 - 10 mm. And above the disk surface, there is a rib provided between any two rows of holes. The height of the rib is 3 - 5 mm and the width is 3 - 8 mm; The stirring paddle is selected from one of stirring paddle A, stirring paddle B, and stirring paddle C. Stirring paddle A is a straight - blade stirring paddle. Stirring paddle B is an inclined - blade stirring paddle, and its blade forms an angle of 30° with the horizontal plane. Stirring paddle C is an inclined - blade stirring paddle, and its blade forms an angle of - 30° with the horizontal plane.

10. A composite material spray forming device based on in-situ reaction of melt dispersion according to claim 7, characterized in that: The outer part of the composite reaction crucible is surrounded by an electromagnetic induction coil; The nozzle faces the top surface of the tray; The spraying device further includes a swinging mechanism, and the swinging mechanism is used to swing the nozzle synchronously.

Images